Artificial leg



(No Mode1.)

Eg; H. ERICKSSON. ARTIFICIAL LEG.

NITED STATES' N;

ERIC `I-I. EEIcKssorLbE sT. PAUL, MINNESOTA.

ARTIFICIAL LEG.

SPECIFICATION forming part of Letters Patent No. 527,525, dated octoberIe, 1894. j Applicaties tied August 27, i894. serial 110.521,35.(Nnniaei.) I

To all whom t may concern,.-

I Be it known thatLERIC H. ERIGKSSON, a citizen of the United States,residingin St. Paul, in the county of Ramsey and State of Minnesota,

i have invented certain new andusefulIInprovements in Artificial Legs,of which the following is a specification.

This invention relates to artificial legs,I

` and consists in the construction, combination and arrangement ofparts, as hereinafter set s B3B1 by elastic strips DEIDS, the ends ofthe s forth, and specifically pointed out in the claims. C I I In thedrawings; Figure l is a Iside elevation. Fig. 2` is a rear elevation.Fig. 3 is a longitudinal section on theline aux of Fig. 2.` Fig.4 is across sectionon the line y y of` Fig. 2.` Fig. is anenlarged sectionaldetail of the knee joint, and Fig.` 6 is an enlarged sectional view ofthe same. Fig. 7 is a cross sectional view of the slip socket,illustrating itsconstruction. Figs. 8, 9, and l0 are `perspective viewsof the three parts of the cast f I fof the stump of` theamputated limbover which the slip socket is formed,k illustrating its construction.

A represents the foot portion, A2 the lower leg portion, and A3 theportion laced or strapped around the thigh, these parts being of theusual construction. The thigh portion A3 is provided with metal straps BB2 extending below its lower part, and each terminating in a socket aadapted to be clasped by rbolts a2 between ears a3 on standards Bs B4rising from each side of the leg portion A2, as shown. The portion ofthe upper ends of the standards B8 B4 are cut out at o', (see Figs. 5and 6,) and adapted to receive a lug` b2, on a small stop plate b3,Fitting between the ears a3 and with its upper surface in contact withthe lower surface of the socket a. The

. lower portion of the socket a is flattened as as well as toadjust themovement of the joint.

` and symmetrical form is produced, which cor- By this simplearrangement a noiseless joint is formed, so that no unpleasant metallicrattling is heard when the leg is in use. The standards B3B4 arebifurcated, or forked, as shown at B5 B, and adapted to form guides fora socketD" which slides up and down between the standards, being`supported from turning or` moving s sidewise s by ribs d, as shown.' I

The socket D is connected to the standards elastic being secured attheir upper endsby clamps e', to the standards, and at their lower endsby the clamps e2 to the socket D', as shown. By thisV means the socketis held normally upward to its `highest position.

The upper portion of the lowerlegportion` A2, is formed hollow, and witha sleeve Dflit` ting into its upper part, the upper portion of thesleeve `forming a socket or step for the some other suitable `lightmaterial, and cov-` ered withbuckskin or other leather, 'or othersimilar suitable material, to avoid `noiseor unnecessary frictionbetween the parts.

The socket D is formed "to fit over the stump of the amputated limb,andthe manner of forming and constructing it is an important feature ofmy invention,which I will now describe.

A plaster of paris cast is first made of the stump of the severed limb,and a wedge shaped plate E', (see Fig. 10,) inserted into the matrixthus formed. The semi-liquid plaster of paris is then poured into thematrix on each sideof the central dividing plate E', to form the cast.When the material is set sufciently, the wedge plate isremoved, whichpermits the two side sections E2 E3, (see Figs. 7, 8, and 9,) to bereadily removed from the matrix, to thus permit the ready removal of thesections EZE3 from the matrix being the function of the wedge plate E.placing the three portions E E2 E8 together again, as shown in Fig. 7,anexact model of the severed stump is produced. I then mold around thecast thus formed, a covering of rawfhide previously soaked to render itpliable, and on the outside of thisraw-hide cov ering I glue, orotherwise secure, small strips of soft light wood, until a somewhatrounded Then by responds to the shape of the corresponding portion ofthe other or sound limb, and also to conform to the shape of the upperportion of the lower leg section A2, as shown, the lower end beingformed to fit the sleeve D4, as shown in Fig. 3. The wood filling isthen covered with a layer of raw-hide molded thereon while in a plasticstate. When the raw hide has become dried, a very hard, tough socket isproduced, which at the same time is very much lighter than anyfotherconstruction with which I am acquainted.

The inner layer of raw-hide is designated by F', the wood filling by F2,and the outer coating of raw-hide by F3, as shown in Fig. 3.

The socket D is open at the bottom, so that the air has free access tothe end of the stump of the severed limb, which is a very desirable andnecessary feature to secure proper ventilation.

By this simple arrangement a very free easy working joint is obtained,and a exible natural movement, which renders the limb very convenientand agreeable to the wearer, and noiseless when in use. By thisconstruction also the slip of the joint is between the `socket andsleeve and lower leg portion, and not between the socket and the severedstump, as in someforms of artificial limbs.

The socket is held at all times in close contact with the stump of thesevered limb, and `there is consequently no friction between the iaturallimb and any portion of the artificial imb.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is-

l. In an artificial limb, the thigh portion having the straps providedwith sockets, the lower leg portion having the straps provided with earsand united by pivot bolts, in combination with adjustable cushionedstops, whereby the movement of the lower limb portion may be adjustedand the joint rendered noiseless, substantially as and for the purposeset forth.

2. In an artificial limb, the thigh portion and lower limb portionsunited by jointed straps, a socket molded to the stump of the severedlimb, and slidable vertically between said straps, and ay sleeve betweenthe lower leg portion and said socket, substantially as and for thepurpose set forth.

3. In an artificial limb, the thigh portion and lower limb portionsunited by jointed straps, a socket molded to the stump of the severedlimb, and slidable vertically between said straps, a sleeve between thelower leg portion and said socket, and elastic supporting straps unitingsaid socket to said straps, substantially as and for the purpose setforth.

4. The method of constructing the socket for the stump of a severed limbin an artiicial leg, consisting in first forming a matrix by molding,then inserting into said matrix a wedge shaped dividing plate, thentaking a cast of the portion of the matrix not occupied by said Wedgeshaped plate, then removing said wedge shaped plate, and sections ofsaid cast, then reunitingv said cast sec,- tions and wedge shaped plateto form a cast on which the socket for the stump of the severed limb canbe molded, substantially as and for the purpose set forth.

In testimony whereof I have hereunto set my hand in the presence of twosubscribing witnesses.

ERIC H. ERICKSSON.

Witnesses:

JOHN E. ERICKSON, C. N. WooDwARD.

